function foo(type: number | string) {
  // 主要针对 第三方库 和类型体操
  switch (typeof type) {
    case "number":
      console.log("number");
      break;
    case "string":
      console.log("string");
      break;
    default:
      const check: never = type;
      break;
  }
}
export {};
